The present invention relates to a continuous-flow heater. Continuous-flow heaters are generally known from EP 2 295 886 A2. The present invention provides a way in which the efficiency of such a continuous-flow heater can be increased.
With a continuous-flow heater according to this disclosure a plurality of ribs are arranged on a front side of the heater housing and on a rear side of the heater housing opposite the front side, said ribs defining, between themselves, a sequence of flow channel portions. The heater housing is thus arranged in an interior of the continuous-flow heater. Liquid to be heated flows from the inlet opening to the outlet opening of the continuous-flow heater and thereby flows both along the front side and along the rear side of the heater housing from one flow channel portion to the next adjacent flow channel portion. The ribs can be integrally moulded on the outer housing or can be part of the heater housing. The ribs have a dual function since on the one hand they define the channel portions through which the liquid to be heated flows and on the other hand enlarge the heat transfer area. Heat is therefore transferred very efficiently to the liquid to be heated.
The liquid flow can be divided in the continuous-flow heater into two halves. One half then flows along the front side of the heater housing, and the other half then flows along the rear side. It is also possible for the entire liquid flow to be guided initially along one of the two sides, for example the front side, and then along the other side, for example the rear side.
The heater housing may be an extruded profile, for example, which has one or more chambers, in each of which at least one electric heating element, for example a ceramic PTC element, is arranged.
A plurality of heating elements can be arranged in each tubular chamber of the heater housing. The heating elements in a tubular chamber form a heating rod. Each heating rod contains one or two contact plates, and may also contain a frame, which connects the contact plate(s) to the heating elements to form a unit that can be easily handled during the installation process.
In an advantageous refinement of this disclosure, the heater housing has a plurality of tubular chambers extending parallel to the ribs, and the ribs are arranged centrally above the chambers. Heat that is generated by heating elements arranged in the chambers can thus be delivered particularly efficiently.
In an advantageous refinement of this disclosure, the housing of the continuous-flow heater, which comprises the inlet opening and the outlet opening, is composed of a flat tube and two closure parts, which are attached at the ends of the flat tube. The flat tube and the two closure parts can be locked or welded to one another, for example. The flat tube can be produced as an extruded profile. Alternatively or additionally to ribs of the heater housing, the flat tube can be provided with ribs in order to define flow channel portions.
The flow path of the liquid to be heated can be formed by the configuration of the closure parts, such that the liquid flows along the front side and along the rear side of the heater housing in series or is divided into two parts, one of which flows only along the front side and the other of which flows only along the rear side of the heater housing.
The inlet and outlet openings and electrical connections of the heating elements can be integrated in the closure parts. The inlet opening and the outlet opening may be arranged in different closure parts or in the same closure.